Although not commercially available, various autonomous vehicles are under development. Such autonomous vehicles include control systems for navigating the autonomous vehicle. The control systems are capable of optimizing the speed of the vehicle based on constraints imposed by the road. Autonomous vehicles generally navigate on highways in the presence of other vehicles, which are expected to follow typical behavioral patterns of vehicles. Accordingly, the autonomous vehicle may plan a path to avoid the other vehicles while attempting to optimize the speed of the vehicle.
Urban environments pose challenges for navigation of autonomous vehicles. Not only does the autonomous vehicle determine a route to follow, the autonomous vehicle also accounts for unpredictable factors, such as pedestrians. Although pedestrian detection and response is a recognized problem, autonomous vehicles typically handle pedestrians separately from standard speed control. Accordingly, stopping for a pedestrian may not be well-integrated into the vehicle's speed planning. When a vehicle reacts to an unpredictable factor, a sudden change in vehicle behavior may subject passengers to unexpected forces, reducing passenger comfort. For example, the first derivative of acceleration, also known as “jerk,” is associated with the forces experienced by the passenger. Stopping for a pedestrian may generate a high level of negative jerk as the vehicle rapidly decelerates to avoid contact with the pedestrian. This high level of jerk may cause passengers to feel uncomfortable or even unsafe in the autonomous vehicle.
In view of the foregoing, there is a need for trajectory planning for autonomous vehicles that provides passenger comfort by controlling jerk while stopping for unexpected obstacles. Further advantages will become apparent from the disclosure provided below.